// Copyright 2014 The JINBAO Authors
// This file is part of the JINBAO library.
//
// The JINBAO library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The JINBAO library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the JINBAO library. If not, see <http://www.gnu.org/licenses/>.

// Package p2p implements the Ethereum p2p network protocols.
package p2p

import (
	"context"
	"crypto/ecdsa"
	"errors"
	"fmt"
	"github.com/cc14514/go-alibp2p"
	"github.com/cc14514/go-uxgklib"
	"github.com/yunhailanuxgk/go-jinbao/params"
	"math/big"
	"net"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/yunhailanuxgk/go-jinbao/event"
	"github.com/yunhailanuxgk/go-jinbao/log"
	"github.com/yunhailanuxgk/go-jinbao/p2p/discover"
	"github.com/yunhailanuxgk/go-jinbao/p2p/discv5"
	"github.com/yunhailanuxgk/go-jinbao/p2p/nat"
	"github.com/yunhailanuxgk/go-jinbao/p2p/netutil"
)

const (
	defaultDialTimeout      = 15 * time.Second
	refreshPeersInterval    = 30 * time.Second
	staticPeerCheckInterval = 15 * time.Second

	// Maximum number of concurrently handshaking inbound connections.
	maxAcceptConns = 50

	// Maximum number of concurrently dialing outbound connections.
	maxActiveDialTasks = 16

	// Maximum time allowed for reading a complete message.
	// This is effectively the amount of time a connection can be idle.
	frameReadTimeout = 30 * time.Second

	// Maximum amount of time allowed for writing a complete message.
	frameWriteTimeout = 20 * time.Second
)

var errServerStopped = errors.New("server stopped")

// Config holds Server options.
type Config struct {
	NetworkId uint64

	// This field must be set to a valid secp256k1 private key.
	PrivateKey *ecdsa.PrivateKey `toml:"-"`

	// MaxPeers is the maximum number of peers that can be
	// connected. It must be greater than zero.
	MaxPeers int

	// MaxPendingPeers is the maximum number of peers that can be pending in the
	// handshake phase, counted separately for inbound and outbound connections.
	// Zero defaults to preset values.
	MaxPendingPeers int `toml:",omitempty"`

	// NoDiscovery can be used to disable the peer discovery mechanism.
	// Disabling is useful for protocol debugging (manual topology).
	NoDiscovery bool

	// DiscoveryV5 specifies whether the the new topic-discovery based V5 discovery
	// protocol should be started or not.
	DiscoveryV5 bool `toml:",omitempty"`

	// Listener address for the V5 discovery protocol UDP traffic.
	DiscoveryV5Addr string `toml:",omitempty"`

	// Name sets the node name of this server.
	// Use common.MakeName to create a name that follows existing conventions.
	Name string `toml:"-"`

	// BootstrapNodes are used to establish connectivity
	// with the rest of the network.
	BootstrapNodes        []*discover.Node
	Alibp2pBootstrapNodes []string

	// BootstrapNodesV5 are used to establish connectivity
	// with the rest of the network using the V5 discovery
	// protocol.
	BootstrapNodesV5 []*discv5.Node `toml:",omitempty"`

	// Static nodes are used as pre-configured connections which are always
	// maintained and re-connected on disconnects.
	StaticNodes []*discover.Node

	// Trusted nodes are used as pre-configured connections which are always
	// allowed to connect, even above the peer limit.
	TrustedNodes []*discover.Node

	// Connectivity can be restricted to certain IP networks.
	// If this option is set to a non-nil value, only hosts which match one of the
	// IP networks contained in the list are considered.
	NetRestrict *netutil.Netlist `toml:",omitempty"`

	// NodeDatabase is the path to the database containing the previously seen
	// live nodes in the network.
	NodeDatabase string `toml:",omitempty"`

	// Protocols should contain the protocols supported
	// by the server. Matching protocols are launched for
	// each peer.
	Protocols []Protocol `toml:"-"`

	// If ListenAddr is set to a non-nil address, the server
	// will listen for incoming connections.
	//
	// If the port is zero, the operating system will pick a port. The
	// ListenAddr field will be updated with the actual address when
	// the server is started.
	ListenAddr string

	// If set to a non-nil value, the given NAT port mapper
	// is used to make the listening port available to the
	// Internet.
	NAT nat.Interface `toml:",omitempty"`

	// If Dialer is set to a non-nil value, the given Dialer
	// is used to dial outbound peer connections.
	Dialer NodeDialer `toml:"-"`

	// If NoDial is true, the server will not dial any peers.
	NoDial bool `toml:",omitempty"`

	// If EnableMsgEvents is set then the server will emit PeerEvents
	// whenever a message is sent to or received from a peer
	EnableMsgEvents bool

	// Logger is a custom logger to use with the p2p.Server.
	Logger log.Logger
}

// Server manages all peer connections.
type Server struct {
	// Config fields may not be modified while the server is running.
	Config

	// Hooks for testing. These are useful because we can inhibit
	// the whole protocol stack.
	newTransport func(net.Conn) transport
	newPeerHook  func(*Peer)

	lock    sync.Mutex // protects running
	running bool

	ntab         discoverTable
	listener     net.Listener
	ourHandshake *protoHandshake
	lastLookup   time.Time
	DiscV5       *discv5.Network

	// These are for Peers, PeerCount (and nothing else).
	peerOp     chan peerOpFunc
	peerOpDone chan struct{}

	quit          chan struct{}
	addstatic     chan *discover.Node
	removestatic  chan *discover.Node
	posthandshake chan *conn
	addpeer       chan *conn
	delpeer       chan peerDrop
	loopWG        sync.WaitGroup // loop, listenLoop
	peerFeed      event.Feed
	log           log.Logger

	// add by liangc >>>>
	alibp2pService *Alibp2p
}

type peerOpFunc func(map[discover.NodeID]*Peer)

type peerDrop struct {
	*Peer
	err       error
	requested bool // true if signaled by the peer
}

type connFlag int

const (
	dynDialedConn connFlag = 1 << iota
	staticDialedConn
	inboundConn
	trustedConn
)

// conn wraps a network connection with information gathered
// during the two handshakes.
type conn struct {
	fd net.Conn
	transport
	flags          connFlag
	cont           chan error      // The run loop uses cont to signal errors to SetupConn.
	id             discover.NodeID // valid after the encryption handshake
	caps           []Cap           // valid after the protocol handshake
	name, session  string          // valid after the protocol handshake
	alibp2pservice *Alibp2p
}

type transport interface {
	// The two handshakes.
	doEncHandshake(prv *ecdsa.PrivateKey, dialDest *discover.Node) (discover.NodeID, error)
	doProtoHandshake(our *protoHandshake) (*protoHandshake, error)
	// The MsgReadWriter can only be used after the encryption
	// handshake has completed. The code uses conn.id to track this
	// by setting it to a non-nil value after the encryption handshake.
	MsgReadWriter
	// transports must provide Close because we use MsgPipe in some of
	// the tests. Closing the actual network connection doesn't do
	// anything in those tests because NsgPipe doesn't use it.
	close(err error)
}

func (c *conn) String() string {
	s := c.flags.String()
	if (c.id != discover.NodeID{}) {
		s += " " + c.id.String()
	}
	s += " " + c.fd.RemoteAddr().String()
	return s
}

func (f connFlag) String() string {
	s := ""
	if f&trustedConn != 0 {
		s += "-trusted"
	}
	if f&dynDialedConn != 0 {
		s += "-dyndial"
	}
	if f&staticDialedConn != 0 {
		s += "-staticdial"
	}
	if f&inboundConn != 0 {
		s += "-inbound"
	}
	if s != "" {
		s = s[1:]
	}
	return s
}

func (c *conn) is(f connFlag) bool {
	return c.flags&f != 0
}

// Peers returns all connected peers.
func (srv *Server) Peers() []*Peer {
	var ps []*Peer
	select {
	// Note: We'd love to put this function into a variable but
	// that seems to cause a weird compiler error in some
	// environments.
	case srv.peerOp <- func(peers map[discover.NodeID]*Peer) {
		for _, p := range peers {
			ps = append(ps, p)
		}
	}:
		<-srv.peerOpDone
	case <-srv.quit:
	}
	return ps
}

// PeerCount returns the number of connected peers.
func (srv *Server) PeerCount() int {
	var count int
	select {
	case srv.peerOp <- func(ps map[discover.NodeID]*Peer) { count = len(ps) }:
		<-srv.peerOpDone
	case <-srv.quit:
	}
	return count
}

// AddPeer connects to the given node and maintains the connection until the
// server is shut down. If the connection fails for any reason, the server will
// attempt to reconnect the peer.
func (srv *Server) AddPeer(node *discover.Node) {
	select {
	case srv.addstatic <- node:
	case <-srv.quit:
	}
}

func (srv *Server) Alibp2pAddPeer(url string) error {
	return srv.alibp2pService.Connect(url)
}

// RemovePeer disconnects from the given node
func (srv *Server) RemovePeer(node *discover.Node) {
	select {
	case srv.removestatic <- node:
	case <-srv.quit:
	}
}

// SubscribePeers subscribes the given channel to peer events
func (srv *Server) SubscribeEvents(ch chan *PeerEvent) event.Subscription {
	return srv.peerFeed.Subscribe(ch)
}

// Self returns the local node's endpoint information.
func (srv *Server) Self() *discover.Node {
	srv.lock.Lock()
	defer srv.lock.Unlock()

	if !srv.running {
		return &discover.Node{IP: net.ParseIP("0.0.0.0")}
	}
	return srv.makeSelf(srv.listener, srv.ntab)
}

func (srv *Server) makeSelf(listener net.Listener, ntab discoverTable) *discover.Node {
	// If the server's not running, return an empty node.
	// If the node is running but discovery is off, manually assemble the node infos.
	if ntab == nil {
		// Inbound connections disabled, use zero address.
		if listener == nil {
			return &discover.Node{IP: net.ParseIP("0.0.0.0"), ID: discover.PubkeyID(&srv.PrivateKey.PublicKey)}
		}
		// Otherwise inject the listener address too
		addr := listener.Addr().(*net.TCPAddr)
		return &discover.Node{
			ID:  discover.PubkeyID(&srv.PrivateKey.PublicKey),
			IP:  addr.IP,
			TCP: uint16(addr.Port),
		}
	}
	// Otherwise return the discovery node.
	return ntab.Self()
}

// Stop terminates the server and all active peer connections.
// It blocks until all active connections have been closed.
func (srv *Server) Stop() {
	srv.lock.Lock()
	defer srv.lock.Unlock()
	if !srv.running {
		return
	}
	srv.running = false
	if srv.listener != nil {
		// this unblocks listener Accept
		srv.listener.Close()
	}
	close(srv.quit)
	srv.loopWG.Wait()
}

// Start starts running the server.
// Servers can not be re-used after stopping.
func (srv *Server) Start() (err error) {
	lib.Start()
	srv.lock.Lock()
	defer srv.lock.Unlock()
	if srv.running {
		return errors.New("server already running")
	}
	srv.running = true
	srv.log = srv.Config.Logger
	if srv.log == nil {
		srv.log = log.New()
	}
	srv.log.Info("Starting P2P networking")

	// static fields
	if srv.PrivateKey == nil {
		return fmt.Errorf("Server.PrivateKey must be set to a non-nil key")
	}
	if srv.newTransport == nil {
		srv.newTransport = newRLPX
	}
	if srv.Dialer == nil {
		srv.Dialer = TCPDialer{&net.Dialer{Timeout: defaultDialTimeout}}
	}
	srv.quit = make(chan struct{})
	srv.addpeer = make(chan *conn)
	srv.delpeer = make(chan peerDrop)
	srv.posthandshake = make(chan *conn)
	srv.addstatic = make(chan *discover.Node)
	srv.removestatic = make(chan *discover.Node)
	srv.peerOp = make(chan peerOpFunc)
	srv.peerOpDone = make(chan struct{})

	// add by liangc : libp2p transport
	srv.newTransport = newAlibp2pTransport

	p2pport, err := strconv.Atoi(strings.Split(srv.Config.ListenAddr, ":")[1])
	if err != nil {
		p2pport = 0
	}
	var muxPort = 0
	netid := big.NewInt(0x04A26664BddDa1a)
	if params.IsTestnet() {
		netid = big.NewInt(0)
	} else if params.IsDevnet() {
		netid = big.NewInt(1)
	}
	pub, _ := alibp2p.ECDSAPubEncode(&srv.PrivateKey.PublicKey)
	log.Info("###################################################")
	log.Info(fmt.Sprintf("# port = %d", p2pport))
	log.Info(fmt.Sprintf("# maxpeers = %d", srv.Config.MaxPeers))
	log.Info(fmt.Sprintf("# muxport = %d", muxPort))
	log.Info(fmt.Sprintf("# networkid = %d", netid))
	log.Info(fmt.Sprintf("# bootnode = %v", srv.Config.Alibp2pBootstrapNodes))
	log.Info(fmt.Sprintf("# pubkey = %v", pub))
	log.Info("###################################################")
	ctx := context.Background()
	ctx, cancel := context.WithCancel(ctx)
	go func() {
		<-srv.quit
		cancel()
	}()
	srv.alibp2pService = NewAlibp2p(
		ctx,
		p2pport,
		muxPort,
		srv.Config.MaxPeers,
		netid, srv, nil)

	srv.alibp2pService.Start()

	dialer := newDialState(srv.StaticNodes, srv.BootstrapNodes, srv.ntab, srv.MaxPeers, srv.NetRestrict)

	// handshake
	srv.ourHandshake = &protoHandshake{Version: baseProtocolVersion, Name: srv.Name, ID: discover.PubkeyID(&srv.PrivateKey.PublicKey)}
	for _, p := range srv.Protocols {
		srv.ourHandshake.Caps = append(srv.ourHandshake.Caps, p.cap())
	}

	srv.loopWG.Add(1)
	go srv.run(dialer)
	srv.running = true
	return nil
}

func (srv *Server) startListening() error {
	// Launch the TCP listener.
	listener, err := net.Listen("tcp", srv.ListenAddr)
	if err != nil {
		return err
	}
	laddr := listener.Addr().(*net.TCPAddr)
	srv.ListenAddr = laddr.String()
	srv.listener = listener
	srv.loopWG.Add(1)
	go srv.listenLoop()
	// Map the TCP listening port if NAT is configured.
	if !laddr.IP.IsLoopback() && srv.NAT != nil {
		srv.loopWG.Add(1)
		go func() {
			nat.Map(srv.NAT, srv.quit, "tcp", laddr.Port, laddr.Port, "ethereum p2p")
			srv.loopWG.Done()
		}()
	}
	return nil
}

type dialer interface {
	newTasks(running int, peers map[discover.NodeID]*Peer, now time.Time) []task
	taskDone(task, time.Time)
	addStatic(*discover.Node)
	removeStatic(*discover.Node)
}

func (srv *Server) run(dialstate dialer) {
	defer srv.loopWG.Done()
	var (
		//peers        = make(map[discover.NodeID]*Peer)
		peers = make(map[discover.NodeID]map[string]*Peer)

		//trusted      = make(map[discover.NodeID]bool, len(srv.TrustedNodes))
		//taskdone     = make(chan task, maxActiveDialTasks)
		runningTasks []task
		//queuedTasks  []task // tasks that can't run yet
	)
	// Put trusted nodes into a map to speed up checks.
	// Trusted peers are loaded on startup and cannot be
	// modified while the server is running.
	//for _, n := range srv.TrustedNodes {
	//	trusted[n.ID] = true
	//}
	/*
		// removes t from runningTasks
		delTask := func(t task) {
			for i := range runningTasks {
				if runningTasks[i] == t {
					runningTasks = append(runningTasks[:i], runningTasks[i+1:]...)
					break
				}
			}
		}
		// starts until max number of active tasks is satisfied
		startTasks := func(ts []task) (rest []task) {
			i := 0
			for ; len(runningTasks) < maxActiveDialTasks && i < len(ts); i++ {
				t := ts[i]
				srv.log.Trace("New dial task", "task", t)
				go func() { t.Do(srv); taskdone <- t }()
				runningTasks = append(runningTasks, t)
			}
			return ts[i:]
		}
		scheduleTasks := func() {
			// Start from queue first.
			queuedTasks = append(queuedTasks[:0], startTasks(queuedTasks)...)
			// Query dialer for new tasks and start as many as possible now.
			if len(runningTasks) < maxActiveDialTasks {
				nt := dialstate.newTasks(len(runningTasks)+len(queuedTasks), peers, time.Now())
				queuedTasks = append(queuedTasks, startTasks(nt)...)
			}
		}
	*/
running:
	for {
		//scheduleTasks()

		select {
		case <-srv.quit:
			// The server was stopped. Run the cleanup logic.
			break running
		case <-srv.addstatic:
		//	// This channel is used by AddPeer to add to the
		//	// ephemeral static peer list. Add it to the dialer,
		//	// it will keep the node connected.
		//	srv.log.Debug("Adding static node", "node", n)
		//	dialstate.addStatic(n)
		//case n := <-srv.removestatic:
		//	// This channel is used by RemovePeer to send a
		//	// disconnect request to a peer and begin the
		//	// stop keeping the node connected
		//	srv.log.Debug("Removing static node", "node", n)
		//	dialstate.removeStatic(n)
		//	if p, ok := peers[n.ID]; ok {
		//		p.Disconnect(DiscRequested)
		//	}
		case op := <-srv.peerOp:
			// This channel is used by Peers and PeerCount.
			rpeers := make(map[discover.NodeID]*Peer)

			for pid, pmap := range peers {
				for _, p := range pmap {
					rpeers[pid] = p
					break
				}
			}
			op(rpeers)
			srv.peerOpDone <- struct{}{}
		//case t := <-taskdone:
		//	// A task got done. Tell dialstate about it so it
		//	// can update its state and remove it from the active
		//	// tasks list.
		//	srv.log.Trace("Dial task done", "task", t)
		//	dialstate.taskDone(t, time.Now())
		//	delTask(t)
		case c := <-srv.posthandshake:
			// A connection has passed the encryption handshake so
			// the remote identity is known (but hasn't been verified yet).
			//if trusted[c.id] {
			//	// Ensure that the trusted flag is set before checking against MaxPeers.
			//	c.flags |= trustedConn
			//}
			// TODO: track in-progress inbound node IDs (pre-Peer) to avoid dialing them.
			select {
			case c.cont <- srv.encHandshakeChecks(peers, c):
			case <-srv.quit:
				break running
			}
		case c := <-srv.addpeer:
			// At this point the connection is past the protocol handshake.
			// Its capabilities are known and the remote identity is verified.
			err := srv.protoHandshakeChecks(peers, c)
			if err == nil {
				// The handshakes are done and it passed all checks.
				p := newPeer(c, srv.Protocols)
				// If message events are enabled, pass the peerFeed
				// to the peer
				if srv.EnableMsgEvents {
					p.events = &srv.peerFeed
				}
				name := truncateName(c.name)
				srv.log.Debug("Adding p2p peer", "name", name, "peers", len(peers)+1)
				go srv.runPeer(p)
				pmap, ok := peers[c.id]
				if !ok {
					pmap = make(map[string]*Peer)
				}
				pmap[c.session] = p
				peers[c.id] = pmap
				//建立链接后发送自己node信息
				//log.Debug("addpeer > session ", "new-session", c.session)
				pubkey, _ := c.id.Pubkey()
				id, _ := alibp2p.ECDSAPubEncode(pubkey)
				log.Debug("-> addpeer", "id", id, "session", c.session, "pmap", pmap)
			}
			// The dialer logic relies on the assumption that
			// dial tasks complete after the peer has been added or
			// discarded. Unblock the task last.
			select {
			case c.cont <- err:
			case <-srv.quit:
				break running
			}
		case pd := <-srv.delpeer:
			// A peer disconnected.
			pmap, ok := peers[pd.ID()]
			pubkey, _ := pd.ID().Pubkey()
			id, _ := alibp2p.ECDSAPubEncode(pubkey)
			//dellogAdd(id, pd.rw.session)
			if pd.err.Error() == "unlink" {
				delete(peers, pd.ID())
			} else if ok {
				delete(pmap, pd.rw.session)
				log.Debug("<- delpeer : pmap-clean", "id", id, "session", pd.rw.session, "pmap", pmap)
				if len(pmap) == 0 {
					delete(peers, pd.ID())
					log.Debug("<- delpeer : pmap-0", "id", id)
				} else {
					peers[pd.ID()] = pmap
					log.Debug("<- delpeer : pmap-n", "id", id, "pmap", pmap)
				}
			}
			log.Debug("<- delpeer", "err", pd.err, "id", id, "session", pd.rw.session, "pmap", pmap)
		}
	}

	srv.log.Trace("P2P networking is spinning down")

	// Terminate discovery. If there is a running lookup it will terminate soon.
	if srv.ntab != nil {
		srv.ntab.Close()
	}
	if srv.DiscV5 != nil {
		srv.DiscV5.Close()
	}

	// Disconnect all peers.
	for _, pmap := range peers {
		for s, p := range pmap {
			p.Disconnect(DiscQuitting)
			log.Debug("DiscQuitting", "id", s, "session", p.rw.session)
		}
	}
	// Wait for peers to shut down. Pending connections and tasks are
	// not handled here and will terminate soon-ish because srv.quit
	// is closed.
	for len(peers) > 0 {
		select {
		case p := <-srv.delpeer:
			log.Trace("<-delpeer (spindown)", "remainingTasks", len(runningTasks))
			delete(peers, p.ID())
		case <-srv.quit:
			return
		}
	}
}

func (srv *Server) protoHandshakeChecks(peers map[discover.NodeID]map[string]*Peer, c *conn) error {
	// Drop connections with no matching protocols.
	if len(srv.Protocols) > 0 && countMatchingProtocols(srv.Protocols, c.caps) == 0 {
		return DiscUselessPeer
	}
	// Repeat the encryption handshake checks because the
	// peer set might have changed between the handshakes.
	return srv.encHandshakeChecks(peers, c)
}

func (srv *Server) encHandshakeChecks(peers map[discover.NodeID]map[string]*Peer, c *conn) error {
	//switch {
	//case !c.is(trustedConn|staticDialedConn) && len(peers) >= srv.MaxPeers:
	//	return DiscTooManyPeers
	//case peers[c.id] != nil:
	//	return DiscAlreadyConnected
	//case c.id == srv.Self().ID:
	//	return DiscSelf
	//default:
	//	return nil
	//}
	return nil
}

type tempError interface {
	Temporary() bool
}

// listenLoop runs in its own goroutine and accepts
// inbound connections.
func (srv *Server) listenLoop() {
	defer srv.loopWG.Done()
	srv.log.Info("RLPx listener up", "self", srv.makeSelf(srv.listener, srv.ntab))

	// This channel acts as a semaphore limiting
	// active inbound connections that are lingering pre-handshake.
	// If all slots are taken, no further connections are accepted.
	tokens := maxAcceptConns
	if srv.MaxPendingPeers > 0 {
		tokens = srv.MaxPendingPeers
	}
	slots := make(chan struct{}, tokens)
	for i := 0; i < tokens; i++ {
		slots <- struct{}{}
	}

	for {
		// Wait for a handshake slot before accepting.
		<-slots

		var (
			fd  net.Conn
			err error
		)
		for {
			fd, err = srv.listener.Accept()
			if tempErr, ok := err.(tempError); ok && tempErr.Temporary() {
				srv.log.Debug("Temporary read error", "err", err)
				continue
			} else if err != nil {
				srv.log.Debug("Read error", "err", err)
				return
			}
			break
		}

		// Reject connections that do not match NetRestrict.
		if srv.NetRestrict != nil {
			if tcp, ok := fd.RemoteAddr().(*net.TCPAddr); ok && !srv.NetRestrict.Contains(tcp.IP) {
				srv.log.Debug("Rejected conn (not whitelisted in NetRestrict)", "addr", fd.RemoteAddr())
				fd.Close()
				slots <- struct{}{}
				continue
			}
		}

		fd = newMeteredConn(fd, true)
		srv.log.Trace("Accepted connection", "addr", fd.RemoteAddr())

		// Spawn the handler. It will give the slot back when the connection
		// has been established.
		go func() {
			srv.SetupConn(fd, inboundConn, nil)
			slots <- struct{}{}
		}()
	}
}

// SetupConn runs the handshakes and attempts to add the connection
// as a peer. It returns when the connection has been added as a peer
// or the handshakes have failed.
func (srv *Server) SetupConn(fd net.Conn, flags connFlag, dialDest *discover.Node) error {
	self := srv.Self()
	if self == nil {
		return errors.New("shutdown")
	}
	c := &conn{fd: fd, transport: srv.newTransport(fd), flags: flags, cont: make(chan error)}
	err := srv.setupConn(c, flags, dialDest)
	if err != nil {
		c.close(err)
		srv.log.Trace("Setting up connection failed", "id", c.id, "err", err)
	}
	return err
}

func (srv *Server) setupConn(c *conn, flags connFlag, dialDest *discover.Node) error {
	// Prevent leftover pending conns from entering the handshake.
	srv.lock.Lock()
	running := srv.running
	srv.lock.Unlock()
	if !running {
		return errServerStopped
	}
	// Run the encryption handshake.
	var err error
	if c.id, err = c.doEncHandshake(srv.PrivateKey, dialDest); err != nil {
		srv.log.Trace("Failed RLPx handshake", "addr", c.fd.RemoteAddr(), "conn", c.flags, "err", err)
		return err
	}
	clog := srv.log.New("id", c.id, "conn", c.flags)
	// For dialed connections, check that the remote public key matches.
	if dialDest != nil && c.id != dialDest.ID {
		clog.Trace("Dialed identity mismatch", "want", c, dialDest.ID)
		return DiscUnexpectedIdentity
	}
	err = srv.checkpoint(c, srv.posthandshake)
	if err != nil {
		clog.Trace("Rejected peer before protocol handshake", "err", err)
		return err
	}
	// Run the protocol handshake
	phs, err := c.doProtoHandshake(srv.ourHandshake)
	if err != nil {
		clog.Trace("Failed proto handshake", "err", err)
		return err
	}
	if phs.ID != c.id {
		clog.Trace("Wrong devp2p handshake identity", "err", phs.ID)
		return DiscUnexpectedIdentity
	}
	c.caps, c.name = phs.Caps, phs.Name
	err = srv.checkpoint(c, srv.addpeer)
	if err != nil {
		clog.Trace("Rejected peer", "err", err)
		return err
	}
	// If the checks completed successfully, runPeer has now been
	// launched by run.
	clog.Trace("connection set up", "inbound", dialDest == nil)
	return nil
}

func truncateName(s string) string {
	if len(s) > 20 {
		return s[:20] + "..."
	}
	return s
}

// checkpoint sends the conn to run, which performs the
// post-handshake checks for the stage (posthandshake, addpeer).
func (srv *Server) checkpoint(c *conn, stage chan<- *conn) error {
	select {
	case stage <- c:
	case <-srv.quit:
		return errServerStopped
	}
	select {
	case err := <-c.cont:
		return err
	case <-srv.quit:
		return errServerStopped
	}
}

// runPeer runs in its own goroutine for each peer.
// it waits until the Peer logic returns and removes
// the peer.
func (srv *Server) runPeer(p *Peer) {
	if srv.newPeerHook != nil {
		srv.newPeerHook(p)
	}

	// broadcast peer add
	srv.peerFeed.Send(&PeerEvent{
		Type: PeerEventTypeAdd,
		Peer: p.ID(),
	})

	// run the protocol
	remoteRequested, err := p.run()

	// broadcast peer drop
	srv.peerFeed.Send(&PeerEvent{
		Type:  PeerEventTypeDrop,
		Peer:  p.ID(),
		Error: err.Error(),
	})

	// Note: run waits for existing peers to be sent on srv.delpeer
	// before returning, so this send should not select on srv.quit.
	srv.delpeer <- peerDrop{p, err, remoteRequested}
}

// NodeInfo represents a short summary of the information known about the host.
type NodeInfo struct {
	ID    string   `json:"id"`    // Unique node identifier (also the encryption key)
	Name  string   `json:"name"`  // Name of the node, including client type, version, OS, custom data
	Enode string   `json:"enode"` // Enode URL for adding this peer from remote peers
	IP    string   `json:"ip"`    // IP address of the node
	Addrs []string `json:"addrs"` // add by liangc : from alibp2p
	Ports struct {
		Discovery int `json:"discovery"` // UDP listening port for discovery protocol
		Listener  int `json:"listener"`  // TCP listening port for RLPx
	} `json:"ports"`
	ListenAddr string                 `json:"listenAddr"`
	Protocols  map[string]interface{} `json:"protocols"`
}

// NodeInfo gathers and returns a collection of metadata known about the host.
func (srv *Server) NodeInfo() *NodeInfo {
	node := srv.Self()
	/*
		/ip4/127.0.0.1/tcp/10000/ipfs/16Uiu2HAkzfSuviNuR7ez9BMkYw98YWNjyBNNmSLNnoX2XADfZGqP
		/ip4/10.0.0.76/tcp/10000
	*/
	// Gather and assemble the generic node infos
	id, addrs := srv.alibp2pService.Myid()
	enode := id
	for _, addr := range addrs {
		if strings.Contains(addr, "p2p-circuit") || strings.LastIndex(addr, "/ip") != 0 {
			continue
		}
		enode = fmt.Sprintf("%s/ipfs/%s", addr, id)
		break
	}

	info := &NodeInfo{
		Name:  id,
		Enode: enode,
		//Enode:      node.String(),
		Addrs:      addrs,
		ID:         node.ID.String(),
		IP:         node.IP.String(),
		ListenAddr: srv.ListenAddr,
		Protocols:  make(map[string]interface{}),
	}
	info.Ports.Discovery = int(node.UDP)
	info.Ports.Listener = int(node.TCP)

	// Gather all the running protocol infos (only once per protocol type)
	for _, proto := range srv.Protocols {
		if _, ok := info.Protocols[proto.Name]; !ok {
			nodeInfo := interface{}("unknown")
			if query := proto.NodeInfo; query != nil {
				nodeInfo = proto.NodeInfo()
			}
			info.Protocols[proto.Name] = nodeInfo
		}
	}
	return info
}

// PeersInfo returns an array of metadata objects describing connected peers.
func (srv *Server) PeersInfo() []*PeerInfo {
	// Gather all the generic and sub-protocol specific infos
	infos := make([]*PeerInfo, 0, srv.PeerCount())
	for _, peer := range srv.Peers() {
		if peer != nil {
			infos = append(infos, peer.Info())
		}
	}
	// Sort the result array alphabetically by node identifier
	for i := 0; i < len(infos); i++ {
		for j := i + 1; j < len(infos); j++ {
			if infos[i].ID > infos[j].ID {
				infos[i], infos[j] = infos[j], infos[i]
			}
		}
	}
	return infos
}

// add by liangc : 从 IAAS 拿到的 nodes 列表，反序列化以后丢入 nursery 集合，刷新组网节点
func (srv *Server) SetFallbackNodes(urls []string) error {
	boots := make([]string, 0)
	for _, u := range urls {
		boots = append(boots, strings.Replace(u, "pdx", "ipfs", -1))
	}
	log.Info("set-bootnodes", "nodes", boots)
	err := srv.alibp2pService.p2pservice.SetBootnode(boots...)
	if err != nil {
		return err
	}
	return srv.alibp2pService.BootstrapOnce()
}

func (srv *Server) Alibp2pPeers() map[string]interface{} {
	m := make(map[string]interface{})
	d, r, t := srv.alibp2pService.p2pservice.Peers()
	m["direct"], m["relay"], m["total"] = d, r, t
	return m
}
